Thanks for the bug report. When the freeze happens, can you still move the mouse pointer? In a Xorg session, a moving mouse pointer would mean it is only gnome-shell that froze and not Xorg itself.
Next time it happens, please: 1. Wait 10 seconds. 2. Reboot. 3. Run: journalctl -b-1 > prevboot.txt 4. Attach the resulting text file here. ** Package changed: xorg (Ubuntu) => xorg-server (Ubuntu) ** Changed in: xorg-server (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/2102006 Title: Xorg freeze To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/2102006/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp